The present invention relates to an electric conversion stage, capable of being connected on one hand to intermediate terminals of a DC voltage electric bus, and on the other hand to output terminals, the conversion stage comprising P switching branches, P being greater than or equal to 2, preferably equal to 3, the switching branches being connected in parallel between the intermediate terminals, each switching branch including first and second controllable electronic switches connected serially and connected to each other by a midpoint, the first switch being connected between the first intermediate terminal and the corresponding midpoint, and the second switch being connected between the second intermediate terminal and the corresponding midpoint, each switch including a semiconductor element and a diode connected in anti-parallel to the semiconductor element, each semiconductor element being switchable between an on state and an off state, and control means for controlling the electronic switches according to a control law.
The present invention also relates to an electric converter, capable of being linked to an AC electrical network including M phase(s), M being greater than or equal to 1, the converter comprising a first conversion stage forming a voltage rectifier and a second conversion stage connected as output of the first conversion stage, the second conversion stage being as defined above.
The invention also relates to a device for converting AC current into a DC current including such an electric converter.
The invention also relates to a terminal for recharging an electric battery, in particular a motor vehicle electric battery, comprising such an electric converter or such a conversion device.
The invention in particular applies to a recharging terminal capable of delivering, as output, a DC voltage comprised between 5 V and 1 kV, preferably comprised between 10 V and 500 V, and a DC current comprised between 0 and 250 A, preferably comprised between 0 and 125 A.
In order to recharge an electric battery, a device is known for converting AC current into a DC current that can be linked to an AC electric network, such as a three-phase network. This conversion device comprises a voltage rectifier connected to the three-phase network, the voltage rectifier being formed by a diode bridge. This conversion device also comprises a Buck converter connected as output of the voltage rectifier and capable of converting a DC voltage from the rectifier into another DC voltage with a lower value.
The Buck converter comprises two input terminals, two output terminals, as well as a switch and a diode that are connected between the input terminals and linked to each other by an intermediate point. The Buck converter also comprises a capacitor connected between the two output terminals and an electromagnetic coil connected between a terminal of the capacitor and said intermediate point. This switch is a semiconductor element, such as a transistor.
However, the transistor and the electromagnetic coil are relatively expensive and also have a significant bulk, the transistor and the electromagnetic coil being dimensioned to allow the passage of strong currents, such as currents of approximately 100 A.